As a method of orthodontic, there has conventionally been employed, for example, a method comprising steps of extracting the first premolar tooth or the like and retracting anterior teeth toward lateral teeth to align the remaining teeth. In such a case, a technique of using an orthodontic metal wire 21 made of stainless steel attached to a large number of brackets 20 fixed to the teeth is available as shown FIG. 6.
The technique shown in FIG. 6, however, has a disadvantage of spoiling the appearance of teeth because the metal wire is placed buccally. For this reason, another technique of placing the brackets 20 and the metal wire 21 lingually is also available, as shown in FIG. 7. In this technique, however, the brackets and metal wire are not easy to set.
Therefore, a technique shown in FIG. 8 is also adopted in some cases, where brackets 20' and a metal wire 21' are set on the lingual side of the anterior teeth F only, while, for lateral teeth S, brackets 20" and a metal wire 21" are provided on the buccal side of the lateral teeth S, the lateral teeth S and the anterior teeth F are coupled to each other with metal wires 22 and further the anterior teeth F is pulled toward the lateral teeth S by biasing means 23 such as elastic modules.
In the technique shown in FIG. 8, however, as the anterior teeth F is supported only by the metal wires 22, the metal wires 22 deflect, causing obstruction to the tooth alignment. While the tooth alignment, since the biasing means 23 keeps biasing the anterior teeth F toward the lateral teeth S, the distance between the anterior teeth F and the lateral teeth S becomes shorter gradually with a lapse of time. Unfortunately, because no means of absorption therefor is provided, the metal wire 22 would need to be readjusted for its shape, length and the like. As a result, this work would cause a complexity.